While in the Cimarron jail, wild and hot tempered cowpoke ""Screamer"" witnesses outlaw Ace Coffin commit the cold-blooded murder of a fellow bank robber. Knowing that there is a $10,000 price on Coffin's head, Screamer offers to help Crown track down the killer and his band of outlaws.
With a little help from his old gang, widely known outlaw Jud Starr slips the hangman's noose and begins a law breaking rampage over the entire Cimarron Strip. Upon discovering that Starr and his gang are using the Cherokee Outlet as a place of refuge, Marshal Crown sets out to track them down.
There is trouble in Cimarron when Jing McQueen, the drunken son of wealthy cattleman Mike McQueen, shoots a local preacher and burns down a livery stable. When the preacher recovers, he refuses to press charges, and McQueen is released from jail, leaving Marshal Crown to control an angry lynch mob.
When a potential range war heats up between cattlemen and incoming settlers in the Outlet, Washington sends U.S. Marshal Jim Crown to the Cimarron Territory to quell the dispute. Assigned to Cimarron City, Crown finds that there is no law in the town, and that he will receive no help from the Army. Crown is forced to jail his old buddy ""Bear"", accompanied by sidekick Mobeetie, and his gang of renegade cowboys, when they go on a free-for-all drunk and terrorize Cimarron. Upon their release from jail, the cowboys discover that their boss, cattleman Hardy Miller, has lost his government land lease, due to the government favoring the movement of the incoming farmers and settlers. When Miller is forced to fire Bear and his group, they promise revenge against the settlers and vow to turn the Cimarron River bloody red.
When Wilcat Gallagher's Wild West Show hits Cimarron, trouble starts when the shows main attraction features the reenactment of a cavalry slaughter of Indians called, The Battle Of Bloody Stones. When Indians in the Cimarron territory become angry with the way that the battle is portrayed, conflict erupts between the Indians and Wildcat Gallagher's band.
Gang leader Arn Tinker gives 19-year-old gang member Whitey false information about their next robbery. Whitey winds up kidnapping Dulcey, promising her a safe return only after Tinker is arrested and hanged for his past crimes.
Cavalry veteran Sergeant Bill Disher is driven to drunken rage when his close friend Little Tom is killed in an accident. Disher bitterly blames the modernization and expansion of the West, and burns down Cimarron's funeral parlor.
When killer Dickie Vardeman is arrested for murder, Marshal Crown suspects the outlaw Vardeman clan will try to rescue him, and sends the killer by train to a neighboring town for trial.
With Marshal Crown out of town, acting Deputy Marshal MacGregor pursues escaped hired gunman Luther Happ. After tracking down the escaped fugitive and killing him in a shootout, the wounded MacGregor passes out and awakens in a Texas jail, where he is accused by Sheriff Jack Hawkes of murdering Deputy Luther Happ.
Marshal Crown tries to prevent the Houston clan from entering the Mocane Valley before it's open for settlement. The Houston's believe they'll have little competition for prime land because of the legend of a malevolent beast thought to lurk in the valley. When the wagon train is destroyed and most of its travelers killed, Marshal Crown and his men search for the culprits not knowing if their quarry is man or beast.
When wanted killers/brothers Felix and Gene Gauge turn themselves in to Marshal Crown and proclaim self-defense in a killing, they become the prime targets of other bounty hunters. With a $15,000 bounty on their heads, a local wealthy rancher hires a couple of ruthless henchmen to gun down the two brothers.